The objective of the proposed research are to study the biosynthesis of marine toxins, especially saxitoxin, gonyautoxins, and tetrodotoxin with an intention to lay the foundation for a broader study of marine natural products biosynthesis. The ultimate goals of this research are to elucidate the sites of formation and unique metabolic pathways in marine organisms and also to open the way to biosynthetically patterned synthesis of physiologically important products and their derivatives. This information will be applied to both marine ecology and biomedical areas. It is also intended to prepare the selectively labelled derivatives of those pharmacologically important compounds. The work will be a joint effort combining the expertise of the University of Rhode Island group in area of marine natural product chemistry and that of the Purdue group in the area of biosynthesis.